Regular Article

Recombinant scorpion insectotoxin AaIT kills specifically insect cells but not human cells

Article metrics


The nucleotide sequence deduced from the amino acid sequence of the scorpion insectotoxin AaIT was chemically synthesized and was expressed in Escherichia coli. The authenticity of this in vitro expressed peptide was confirmed by N-terminal peptide sequencing. Two groups of bioassays, artificial diet incorporation assay and contact insecticidal effect assay, were carried out separately to verify the toxicity of this recombinant toxin. At the end of a 24 h experimental period, more than 60% of the testing diamondback moth (Plutella xylostella) larvae were killed in both groups with LC50 value of 18.4 mM and 0.70 μM respectively. Cytotoxicity assay using cultured Sf9 insect cells and MCF-7 human cells demonstrated that the toxin AaIT had specific toxicity against insect cells but not human cells. Only 0.13 μM recombinant toxin was needed to kill 50% of cultured insect cells while as much as 1.3 μM toxin had absolutely no effect on human cells. Insect cells produced obvious intrusions from their plasma membrane before broken up. We infer that toxin AaIT bind to a putative sodium channel in these insect cells and open the channel persistently, which would result in Na+ influx and finally cause destruction of insect cells.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1
Figure 2
Figure 3
Figure 4


  1. 1

    Moskowitz H, Herrmann R, Jones AD, Hammock, BD . A depressant insect-selective toxin analog from the venom of the scorpion Leiurus quinquestriatus hebraeus purification and structure/function characterization. Eur J Biochem 1998; 254:44–9.

  2. 2

    Cestle S, Catterall WA . Molecular mechanisms of neurotoxin action on voltage-gated sodium channels. Biochimie 2000; 82:883–92.

  3. 3

    Carbone E, Wanke E, Prestipino G, Possani LD, Maelicke A . Selective blockage of voltage-dependent K+ channels by a novel scorpion toxin. Nature 1982; 296:90–1.

  4. 4

    Loret EP, Mansuelle P, Rochat H, Granier C . Neurotoxins active on insects: amino acids sequences, chemical modifications, and secondary structure estimation by circular dichroism of toxins from the scorpion Androctonus australis Hector. Biochemistry 1990; 29:1492–501.

  5. 5

    Zlotkin E, Eitan M, Bindokas VP, et al. Functional duality and structural uniqueness of depressant insect-selective neurotoxins. Biochemistry 1991; 30:4814–21.

  6. 6

    Catterall WA . The molecular basis of neuronal excitability. Science 1984; 223:653–61.

  7. 7

    Zlotkin E, Kadouri D, Gordon D, Pelhate M, Martin MF, Rochat H . An excitatory and a depressant insect toxin from scorpion venom both affect sodium conductance and possess a common binding site. Arch Biochem Biophys 1985; 240 :877–87.

  8. 8

    Zhu X, Zhang T, Zhu Y . Cloing and sequencing of two depressant insect neurotoxin cDNAs from Buthus martensii Karsch. Chinese Science Bulletin 1996; 41:1387–91.

  9. 9

    Jiang G, Xu Y, Zhu X, Su Y, Zhu Y . Prokaryotically expressed Buthus martensii Karsch insect depressant toxin has insecticidal effects. Toxicon 2001; 39:469–76.

  10. 10

    Li Y, Tan Z, Ji Y . The binding of BmK IT2, a depressant insect-selective scorpion toxin on mammal and insect sodium channels. Neuroscience Research 2000; 38:257–64.

  11. 11

    Borchani L, Stankiewicz M, Kopeyan C, et al. Purification, structure and activity of three insect toxins from Buthus occitanus tunetanus venom. Toxicon 1997; 35:365–82.

  12. 12

    Lester D, Lazarovici P, Pelhate M, Zlotkin E . Purification, characterization and action of two insect toxins from the venom of the scorpion Buthotus judaicus. Biochim Biophys Acta 1982; 701:370–81.

  13. 13

    Kopeyan C, Mansuelle P, Sampieri F, et al. Primary structure of scorpion anti-insect toxins isolated from the venom of Leiurus quinquestriatus quinquestriatus. FEBS Lett 1990; 261:423–6.

  14. 14

    Eitan M, Fowler E, Herrmann R, Duval A, Pelhate M, Zlotkin E . A scorpion venom neurotoxin paralytic to insects that affects sodium current inactivation: purification, primary structure, and mode of action. Biochemistry 1990; 29:5941–47.

  15. 15

    Zlotkin E, Miranda F, Kopeyan C, Lissitzky S . A new toxic protein in the venom of the scorpion Androctonus australis Hector. Toxicon 1971; 9:9–13.

  16. 16

    Oren DA, Froy O, Amit E, Kleinberger-Doron N, Gurevitz M, Shaanan B . An excitatory scorpion toxin with a distinctive feature: an additional alpha helix at the C terminus and its implications for interaction with insect sodium channels. Structure 1998; 6:1095–103.

  17. 17

    Gershberg E, Stockholm D, Froy O, Rashi S, Gurevitz M, Chejanovsky N . Baculovirus-mediated expression of a scorpion depressant toxin improves the insecticidal efficacy achieved with excitatory toxins. FEBS Lett 1998; 422:132–6.

  18. 18

    Zlotkin E, Rochat H, Kopeyan C, Miranda F, Lissitzky S . Purification and properties of the insect toxin from the venom of the scorpion Androctonus australis Hector. Biochimie 1971; 53:1073–8.

  19. 19

    Darbon H, Zoltkin E, Kopeyan C, Van Rietschoten J, Rochat H . Covalent structure of the insect toxin of the North African scorpion Androctonus australis Hector. Int J Pept Prot Res 1982; 20:320–30.

  20. 20

    Zlotkin E, Fishman Y, Elazar M . AaIT: From neurotoxin to insecticide. Biochimie 2000; 82:869–81.

  21. 21

    Oliveira JCR, Montes de Oca H, Duarte MM, Diniz CR, Fortes-Dias CL . Toxicity of South American snake venoms measured by an in vitro cell culture assay. Toxicon 2002; 40:321–5.

  22. 22

    Zhang Z, Yao L, Hou Y . Construction and application of a high level expression vector containing PRPL promotor. Chinese Journal of Virology 1990; 6:111–6.

  23. 23

    Hurt JD, Tu C, Laipis PJ . Isolation and expression of murine carbonic anhydrase IV. Protein Expression and Purification 1998; 12:7–16.

  24. 24

    Iannacone R, Grieco PD, Cellini F . Specific sequence modifications of a cry3B endotoxin gene result in high levels of expression and insect resistance. Plant Molecular Biology 1997; 34:485–96.

  25. 25

    Kota M, Daniell H, Varma S, Garczynski SF, Gould F, Moar WJ . Overexpression of the Bacillus thuringiensis (Bt) Cry2Aa2 protein in chloroplasts confers resistance to plants against susceptible and Bt-resistant insects. Proc Natl Acad Sci USA 1999; 96:1840–5.

  26. 26

    Huang J, Wei Z, An H, Zhu Y . Agrobacterium tumefaciens-mediated transformation of rice with the spider insecticidal gene conferring resistance to leaffolder and striped stem borer. Cell Research 2001; 11(2):149–55.

  27. 27

    Lu F, Fang J, Chen C . TNF receptor-associated factor-2 binding site is involved in TNFR75-dependent enhancement of TNFR55-induced cell death. Cell Research 2001; 11(3):217–22.

  28. 28

    Rivers DB, Rocco MM, Frayha AR . Venom from the ectoparasitic wasp Nasonia vitripennis increases Na+ influx and activates phospholipase C and phospholipase A2 dependent signal transduction pathways in cultured insect cells. Toxicon 2002; 40:9–21.

  29. 29

    Cohen E, Quistad GB . Cytotoxic effects of arthropod venoms on various cultured cells. Toxicon 1998; 36:353–8.

  30. 30

    Rivers DB, Genco M, Sanchez RA . In vitro Analysis of Venom from the Wasp Nasonia Vitripennis: Susceptibility of Different Cell Lines and Venom-Induced Changes in Plasma Membrane Permeability. In vitro Cell Dev Biol-Animal 1998; 35:102–10.

Download references


This work was supported by a grant from 863 High Technology Program, Chinese Ministry of Science and Technology.

Author information

Correspondence to Yu Xian ZHU.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

JI, S., LIU, F., LI, E. et al. Recombinant scorpion insectotoxin AaIT kills specifically insect cells but not human cells. Cell Res 12, 143–150 (2002) doi:10.1038/

Download citation


  • Scorpion toxin
  • AaIT
  • prokaryotic expression
  • cytotoxicity

Further reading